This Alex Gibney documentary describes the origin of Stuxnet, malware devised by Israel and the United States with grave implications for the future.

With every seemingly miraculous advance comes the potential for its catastrophic misuse. If you’re inclined toward paranoia, Alex Gibney’s sobering documentary “Zero Days,” about the spread of malware, exposes a whole arena of potential terror and calamitous destruction surrounded in secrecy.

We all know that our digital connectedness has a dark side. But online bullying and pornography, for example, are the least of it. The nightmare of push-button nuclear annihilation that has haunted us since the invention of the atomic bomb now has a parallel in the looming specter of large-scale cyberwarfare.